The invention is directed to novel matrix metalloproteinase inhibitors and their use in the treatment of matrix metalloproteinase-mediated disease states. The invention is further directed to combinatorial libraries of the compounds and methods to generate these libraries.
Matrix metalloproteinases, hereinafter referred to as xe2x80x9cMMP""s,xe2x80x9d are a class of proteases which are capable of degrading basement membranes and/or collagen. MMP""s are often also referred to using more specific names, such as collagenases or gelatinases. Unless designated otherwise, the term MMP shall refer to all enzymes which can be classified as matrix metalloproteinases.
The presence of circulating MMP""s is associated with a host of disease states, including endotoxic shock, systemic inflammatory response syndrome (SIRS), metastatic and/or invasive cancer, malaria, as well as the presence of other pathogenic organisms. Elevated MMP levels have also been associated with autoimmune diseases such as arthritis. The appearance of elevated MMP concentrations in a mammal is frequently followed by death of the subject due to vascular leakage (i.e., the leakage of plasma proteins into the tissues) and/or SIRS leading to multiple organ failure. SIRS, as befitting its designation as a xe2x80x9csyndrome,xe2x80x9d is etiologically linked to a host of conditions often leading to fatal consequences, including sepsis syndrome, non-responsive septic shock, multiple organ failure syndrome, immuno-mediated organ injury, pancreatitis, hemorrhage, ischemia, or multiple trauma. Where the precipitating condition is an acute occurence, such as ischemia or multiple trauma, the rise in MMP levels can be extremely rapid and if not quickly stabilized and lowered will cause death. Where the precipitating condition tends toward a more chronic ailment, such as a slowly invading malignancy, the rise in MMP levels tends to mirror the growth pattern of the tumor.
Individual matrix metalloproteinases within the larger class of MMP enzymes are designated numerically. Of particular interest are MMP-2 and MMP-9. These two MMP""s have been clearly and positively correlated to the presence of invasive and/or metastatic cancer, as well as to certain immune system dysfunctions, as noted hereinabove. MMP-2 and MMP-9 fall within a sub-class of MMPs designated xe2x80x9cType IVxe2x80x9d collagenases. Type IV collagenases like MMP-2 and MMP-9 are known to be involved in the breakdown of Type IV collagen, a major component of basement membrane (20 to 70% by total mass). See U.S. Pat. No. 5,866,570, to Liang et al. In mammals, Type IV collagen defines a supramolecular network which maintains the integrity of the basement membrane. Consequently, degradation of Type IV collagen by MMP-2 and MMP-9 is believed to be a critical step in basement membrane degradation. The complete amino acid sequences for both MMP-2 and MMP-9 are known, as are the sequences for the their respective and inactive pre-pro and pro-forms. See U.S. Pat. No. 4,992,537 to Goldberg et al. MMP-2 and MMP-9 can be purchased from several international suppliers, including Sigma, St. Louis, Mo.
Several synthetic MMP inhibitors have been described in the patent literature. For instance, U.S. Pat. No. 5,866,570, to Liang et al., noted above, describes bis(dioxopiperazine) compounds which are potent MMP inhibitors. For descriptions of others compounds and treatments which have been reported as having MMP-inhibitory activity, see U.S. Pat. Nos. 4,235,885; 4,263,293; 4,276,284; 4,297,275; 4,367,233; 4,371,465; 4,371,466; 4,374,765; 4,382,081; 4,558,034; 4,704,383; 4,950,755; and 5,270,447. All of these compounds suffer from certain intractable drawbacks, such as cytoxicity or difficult syntheses, which have limited their in vivo application as MMP inhibitors.
There are also known at least two endogenous MMP inhibitors known as tissue inhibitors of metalloproteinase (TIMP""s): TIMP-1 and TIMP-2. The complete amino acid sequences for these proteinaceous MMP inhibitors are known. See DeClerk et al. (1989) J. Biol. Chem. 264:17445; Boone et al. (1990) Proc. Natl. Acad. Sci. USA 87:2800; Docherty et al. (1985) Nature 318:65; and Carmichael et al. (1986) Proc. Natl. Acad. Sci. USA 83:2407.
The expression of MMP""s in general and collagenases in particular has been studied by several research groups. For instance, Wegus and co-workers have shown that mononuclear phagocytes secrete several different MMP""s, including a 57 kD interstitial collagenase (MMP-1), a 72 kD Type IV collagenase (MMP-2), a 60 kD stromelysin (MMP-3), and a 92 kD Type IV collagenase (MMP-9). This same group has also shown that endotoxin stimulates the secretion of MMP-1, MMP-2, MMP-3, and MMP4 from mononuclear phagocytes in vitro. See Wegus et al. (1990) J. Clin. Invest. 86:1496.
Mononuclear phagocytes are also known to secrete interleukin-1 and tumor necrosis factor, compounds which induce MMP gene expression. See Dayer et al. J. Clin. Invest. (1986) 77:645 and Dayer et al. (1985) J. Exp. Med. 162:2163.
Currently, sepsis, septic shock, and the like are treated symptomatically by supporting respiration, replacing lost blood volume, and administering vasoactive drugs to increase renal and/or cardiac function. Surgery and/or antibiotics are used to remove or kill infectious or malignant agents underlying the condition. However, there remains a long-felt need for effective, non-toxic medicinal compounds which are specific and potent inhibitors of MMP""s.
A first embodiment of the invention is directed to compounds of Formula I or II: 
wherein R1 is selected from the group consisting of H, C1-12-alkyl, C3-8-cycloalkyl, C3-8-cycloalkyl-C1-12-alkyl, amino-C1-12-alkyl, Nxe2x80x94C1-6-alkylamino-C1-12-alkyl, N,N-di-C1-6-alkylamino-C1-12-alkyl, 
and 
wherein R5 and R6 are independently selected from the group consisting of H, C1-6-alkyl, C1-6-alylthio, C1-6-alkoxy, fluoro, chloro, bromo, iodo, and nitro; and X is halo;
wherein R4 is selected from the group recited above for R1, and R7 is selected from the group consisting of 
R2 and R3 are selected from the group consisting of 
wherein R5 and R6 are as described above; and pharmaceutically-suitable salts thereof.
A second embodiment of the invention is directed to solution-phase or resin-bound combinatorial libraries containing any combination of the above-described compounds.
A third embodiment of the present invention is drawn to pharmaceutical compositions for the treatment of MMP-mediated diseases in mammals. The composition includes an amount of one or more of the above-described compounds in an amount effective to inhibit MMP activity, optionally in combination with a pharmaceutically-acceptable carrier. The pharmaceutical composition is effective to inhibit and to treat disorders in which MMP activity plays a role, including endotoxic shock, SIRS, invasive cancers, and metastatic cancers.
A fourth embodiment of the invention is directed to a method of inhibiting or treating MMP-mediated diseases in mammals, including human. The invention thus provides a method of treating a host mammal afflicted with an MMP-mediated disorder, the method comprising administering to the mammal an effective MMP-inhibitory amount of a compound of Formula I or II or a pharmaceutically-acceptable salt thereof, optionally in combination with a pharmaceutically-acceptable carrier. The invention further provides a method of inhibiting and/or preventing MMP-mediated disorders, including invasive and metastatic carcinomas, endotoxic shock, and SIRS, the method comprising administering to a mammal susceptible of developing an MMP-mediated disorder an effective MMP-inhibitory amount of a compound of Formula I or II or a pharmaceutically-acceptable salt thereof, optionally in combination with a pharmaceutically-acceptable carrier.
It has now been found that the subject compounds, including pharmacologically-active isomers and pharmaceutically-acceptable salts thereof, possess potent MMP inhibitory activities. Accordingly, they are useful in the treatment of disease conditions wherein MMP activity is a contributing factor. Most notably, the subject compounds are useful in the treatment of endotoxic shock,(SIRS, multiple organ failure syndrome, and metastatic and invasive cancers.
The subject compounds are also notable in that while they possess potent MMP inhibitory activity, they also have low cytotoxicity and do not inhibit fibroblast motility. Consequently, the compounds can be administered in relatively large concentrations to maximize the benefit of their MMP inhibitory activity, without encountering adverse cytotoxic side effects.
The invention also discloses solid-phase synthetic methodologies to construct diversified combinatorial libraries of the subject peptoid/urea compounds. Detailed herein is a convergent, solid-phase method to synthesize these libraries. Each library contains approximately 100 compounds of known structure and equivalent molarity. A high throughput gelatinase assay can be used to screen and select library members having maximum activity to inhibit gelatinase. A deconvolution technique is also described to target those compounds having the greatest inhibitory activity; these compounds are then resynthesized individually and further characterized or advanced to human clinical trials.
The MMP inhibitors disclosed herein provide novel agents for cancer chemotherapy, especially for treating highly malignant and metastatic tumors.
Further aims, objects, and advantages of the present invention will become apparent upon a complete reading of the Detailed Description which follows.